"I'm so full of feeling"

I'm so full of feeling
I can easily believe
I must be sentimental.
But when I mull this over,
I see it's all in thought,
I felt nothing whatever.

All of us alive spend
One life in living it,
Another,
Thinking it.
And the only life we have
Is split between
The true one and the false.

But which is true
And which is false
No one can explain.
And as we go on living,
And as we spend's the one
That's doomed to thinking.
What ?